In general, in a motor used for a refrigerator, two exciter poles and an exciting coil are separately installed in a stator of a single-phase induction motor.
In the motor used for the refrigerator, two excitor polls and an exciting coil are separately installed at the stator in the single-phase induction motor including a core, a main winding (main coil) and an auxiliary winding (sub-coil).
A rotor of the motor used for the refrigerator includes a magnetic material that facilitates magnetizing and demagnetizing.
An excitation control circuit of the motor used for the refrigerator is a circuit that controls the exciting coil in order to magnetize the magnetic material.
The excitation control circuit includes a feedback coil, a capacitor, a speed response switch and an external controller.
FIG. 1 is schematic view showing the structure of the motor used for the refrigerator according to the related art, which includes a stator 20 and a rotor 40 having a magnetic material.
Here, the operation of the apparatus for controlling the motor of the refrigerator according to the related art will now described.
First, the control apparatus controls such that power is applied to the main winding and the auxiliary winding of the stator 20 of the motor, according to which the rotor 40 is rotated by the power applied to the main winding and the auxiliary winding.
Next, when the rotor 40 reaches a certain speed (synchronous speed 75% to 80%), the exciting coil is excited to magnetize the magnetic material 30 to the rotor 40.
In the apparatus for controlling the motor used for the refrigerator as described above, when started, the rotor including the magnetic material is magnetized by exciting the exciting coil at 75% to 80% of the synchronous speed, and then, the rotor is changed to the synchronous speed, causing a problem that the starting torque is small.